1.What do you know about UNDO data?
2.Define UNDO_RETENTION
UNDO_RETENTION specifies (in seconds) the low threshold value of undo retention.For the AUTOEXTEND undo tablespaces, the system retains undo for at least the time specified in this parameter, and automatically tunes the undo retention period to meet the undo requirements of the queries.

Chapter: 10

1.What is meant by Multiplexing Control Files?
2.What is meant by Flash recovery Area?
3.What are the types of database backup available in oracle 10g?
4.What is meant by Image copies and Backup Sets
5.What does it mean by Incremental backup?
An incremental backup is either a level 0 backup, which includes every block in the data files except blocks that have never been used, or a level 1 backup, which includes only those blocks that have been changed since a previous backup was taken.

2.Write about instance recovery.
Ans: Instance or crash recovery:
• Is caused by attempts to open a database whose files are not synchronized on shutdown
• Is automatic
• Uses information stored in redo log groups to synchronize files
• Involves two distinct operations:
– Rolling forward: Data files are restored to their state before the instance failed.
– Rolling back: Changes made but not committed are returned to their original state.

RMAN is an Oracle utility that you use to manage the backup, restore, and recovery operations on Oracle databases. RMAN has a powerful command language that is independent of the operating system.

2.What does it mean by RMAN repository?

RMAN stores information about its own configuration settings, the target database schema, archived redo logs, and all backup files that are on disk or tape. RMAN repository data is always stored in the control file of the target database.
3.Named the types of incomplete recovery.

A corrupted data block is a block that is not in a recognized Oracle format, or whose contents are not internally consistent. Typically, corruptions are caused by faulty hardware or operating system problems.
5. What is meant by AWR (Automatic Workload Repository)?

The Automatic Workload Repository (AWR) is a collection of persistent system performance statistics owned by SYS. The AWR resides in the SYSAUX tablespace.
6. What is meant by control file?

A control file is a small binary file that describes the structure of the database. It must be available for writing by the Oracle server whenever the database is mounted or opened. Without this file, the database cannot be mounted and recovery or re-creation of the control file is required.
7. What is called flashback database?

With Flashback Database, you can quickly bring your database to an earlier point in time by undoing all the changes that have taken place since that time. This operation is fast, because you do not need to restore backups.
8. What is called flashback table?
With Flashback Table, you can recover a table or tables to a specific point in time without restoring a backup. When you use this feature, the data in tables and their associated objects (indexes, constraints, triggers, and so on) is restored.
9. What is called flashback query?
With the Flashback Query feature, you can perform queries on the database as of a certain time. By using the AS OF clause of the SELECT statement, you can specify the timestamp for which to view the data. This is useful for analyzing a data discrepancy.
10. What are the functionalities of SQL loader?
SQL*Loader loads data from external files into tables of an Oracle database. It has a powerful data parsing engine that puts little limitation on the format of the data in the data file.
11. Write the different types of method of SQL loader.
SQL*Loader provides three methods for loading data:
• Conventional path
• Direct path
• Parallel direct path

12. Describe different types of recovery.

Ans: There are two types of recovery:

• Complete recovery brings the database up to the present, including all data changes made to the point in time when the recovery was requested.
• Incomplete recovery brings the database up to a specified point in time in the past, before the recovery operation was requested.